The Gradual Recutting Of An Indian Table Cut

(via Diamond Cuts in Historic Jewelry:1381-1910) Herbert Tillander writes:

In the Six Voyages of John Baptista Tavernier there is an illustration of the fourth diamond that Tavernier sold to Louis XIV when he returned from his last voyage in 1669. At this point the stone weighed 51 9/16 ct. From Taverniers sketches it was impossible to produce a plausible side view of the gem with the recut Brilliant inscribed. But when I inverted the pictures, as Barbot (1858) and Kluge (1860) had done, the solution became immediately obvious. The first recutting (delivered by Alvarez in 1678) involved a loss of only about 9 ct—from 51 9/16 to 42 10/16 ct. At this stage the crown was only ‘brillianteered’—that is, the forty smallest facets were applied and polished—and the bulky pavilion was left untouched. The 1691 inventory described the stone as cut ‘à facettes, à la mode’, omitting the phrase ‘des deux côtés’.

The gem was finally transformed into a well-made Brilliant in 1786, when most of the old French Crown diamonds were refashioned in Antwerp. Now it weighed only 26¾ ct and was described as ‘un très grand diamant brilliant, forme carrée, coins émousses, de bonne eau, et net’.